Abookstore sells used books at 40% discount off the regular price of the book when it was new. the price of a used book is 18$. what was the regular price of that book when it was new?

The regular price was $30.

Step-by-step explanation:

The bookstore sells used books at 40% discount off the price of new books. This means, after the discount, the price of a used book will be 100% - 40% = 60% of the original price.

Now, if the price of the used book is $18, we know that is is 60% of the price of the book when it was new.

Let us call , the price of the book when it was new, then we know that

(this says that 60% of the original price is $18.)

We solve for and get

The price of the book was $30 when it was new.

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